On JumpHigher [1], an app that helps you improve your vertical leaps, just using your phone camera. It's functional already, but very early, the algorithm took quite a while to nail ( still far from perfect ).
I'm a CEO of a small consulting company, and I love working with startups ( or hate working with huge companies, matter of perspective ), and I always thought that to be better at that we have to be able to launch our own stuff.
Also, I never launched anything solo, working alone is hard for me so this was a challenge. I want to continue working on it on the side for a while.
The main audience for now would be basketball players that want to dunk, or anyone that wants a good leg workout and track the progress.